Ice breaking attachment



Sept. 4, 1962 K. H. DATE 3,052,782

ICE BREAKING ATTACHMENT Filed April 1, 1960 2 Sheets-Sheet 1 I N VE NTOR.

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.dl'vae/vzx United States Patent Ofiice 3,852,782 Patented Sept. 4, 1962 3,052,782 ICE BREAKING ATTACHMENT Kazuo Henry Date, South Milwaukee, Wis, assignor to McGraw-Edison Company, Milwaukee, Wis., a corporation of Delaware Filed Apr. 1, 1960, Ser. No. 19,356 8 Claims. (Cl. 200146) This invention relates to circuit interrupting devices and, more particularly, to an ice breaking attachment therefor.

The invention has particular application to load interrupting switches! of the type shown in Patent No. 2,838,638 to K. H. Date and assigned to the assignee of the instant invention. The device illustrated in this patent is a high voltage air disconnect switch in combination with an auxiliary path load current interrupter. The air disconnect switch includes a switch blade mounted on a rotatable insulator and cooperating fixed contact fingers mounted on a stationary insulator. The circuit interrupter is mounted adjacent the fixed contact fingers and includes bypass contacts mounted on one end and cooperatively engageable by a bypass rod electrically and mechanically connected to the switch blade. This provides a parallel current path so that the circuit may be continued for a short time after the switch blade has moved out of engagement with the contact fingers so that a destructive arc is not drawn therebetween. After the switch blade has cleared the contact fingers and before its fully open position is reached, the circuit interrupter is operated and then the switch blade engages the bypass rod to move it out of engagement with the bypass contacts. When the disconnect switch is reclosed, a reverse operating procedure occurs, that is, the bypass rod engages the bypass contacts, the circuit interrupter is then operated to its closed position and thereafter the switch blade engages the stationary contact fingers. It can be seen that it is extremely important for good electrical contact to be attained between the bypass rod and the bypass contacts so that arcing does not occur as the switch blade is moved into and out of its closed position. Such arcing would, of course, defeat the whole purpose of the circuit interrupter.

It is an object of the invention to provide an ice breaking attachment for the bypass contacts of a load interrupter switch.

It is another object of the invention to provide in a load interrupting switch, ice break mean that is operable to engage the stationary bypass contacts prior to the opening or reclosing thereof. A further object is to provide such a device wherein the ice break member is actuated by the switch blade.

These and other objects and advantages of the invention will become apparent from the detailed description of the invention taken in view of the accompanying drawings in which:

FIGS. 1 and 2 show a load interrupting switch in which the instant invention is usable;

FIGS. 3-5 illustrate one embodiment of the instant invention; and

FIGS. 6-9 illustrate alternate embodiments of the instant invention.

In general terms, the invention comprises the combination of a load interrupting switch and an ice break mem ber operable by the switch blade to engage the stationary bypas contacts prior to the engagement and disengagement of the bypass rod therewith so that ice formed on the stationary bypass contacts will be removed.

FIG. 1 shows a three-insulator, rotating, vertical break, air disconnect switch designated generally by the reference numeral 10, in combination with an auxiliary path load interrupter generally designated 12. Switch 10 includes a stationary contact 13 mounted on a metal terminal adaptor 14 which in turn is supported on a stationary insulator 15. A switch blade 16 is mounted on a rotatable central insulator 18 for vertical swinging movement, into and out of engagement with the stationary contacts 13 when the insulator 18 is rotated. The disconnect switch 13 is described in detail in Patent No. 2,830,144 to T. A. Fjellstedt which is assigned to the assignee of the instant invention.

The auxiliary path load interrupter 12, which cooperates with air disconnect switch 10, is mounted on a conductive base 28 integral with the stationary contact terminal adaptor 14. From the foregoing description it is evident that the main current path through disconnect switch it commences at adaptor 14, extends through the contacts 13, switch blade 16 and terminates in outgoing adaptor 212 which forms a part of the switch frame 23 and which is in electrical engagement with the switch blade 16.

Load interrupter 12 includes a hollow porcelain bushing 24 which contains fixed and movable contacts disposed in an arc extinguishing chamber, none of which are shown. Operating mechanism for the movable contact is disposed in a metallic housing 26 mounted on the upper end of bushing 24. The circuit through interrupter 12 commences at the base and terminal adaptor 2t through the fixed and movable contacts of the load interrupter 12 and then to the metallic housing 26. The load interrupter 12 is described in detail in Patent No. 2,886,673 to A. Van Ryan.

The load interrupt-er i2, is actuated by switch blade 16 oscillating a pair of external, triangularly shaped operating arms 35 which are aflixed to a transverse operating shaft 36 extending through housing 26. Trip arms 35 are bridged exteriorly of the housing 26 by a pair of cross rods 38 and 39 which are spaced apart at its outer corners. It will be noted with reference to FIG. 2 that as the main switch blade 16 swings in a vertical plane, its outer end engages trip arms 35 between cross rods 38 and 39. When switch blade 16 has opened sufiiciently to strike across rod 38, trip arms 35 will be rotated in a counterclockwise direction from their phantom position to their position shown by full lines, whereupon the circuit interrupt-er 12 will be opened. Similarly, when switch blade 16 is rotated from its opened to its closed position, it will engage cross rod 39 to return trip arms 35 to their phantom position whereupon the load interrupter 12 is again reclosed. It will be appreciated that switch arm 16 engages cross bar 38 to open the load interrupter 24 after it has parted from the stationary contacts 13, and conversely upon reclosing that it will engage cross bar '39 to reclose load interrupter 12 prior to its re-engagement with the stationary contacts 13.

The bypass circuit also includes fixed bypass contacts 42 affixed to the metal ic housing 26 and a conductive bypass rod 44- in electrical contact with frame 23 and mounted thereon for rotation in a vertical plane as viewed in FIG. 1. The fixed bypass contacts 42 comprise a pair of resilient conductive rod-like members 45 which are affixed at one end to the metallic housing 26 and whose free ends are engageable by the contact rod 44. As explained more fully in the aforementioned Date patent, bypass rod 44 will be engaged by switch blade 16 after the latter has rotated operating arms 35 to their open position, so that the bypass contacts 42 and 44 will not be parted until after circuit interrupter 12 has been opened. Likewise, when switch blade 16 is reclosed, bypass rod 44 will engage stationary bypass contacts 42 prior to the engagement of cross bar 39 by switch blade 16 so that the bypass contacts will be reclosed prior to the reclosure of the circuit interrupter contacts. This insures that the bypass circuit will be open when the bypass contacts open or reclose, so that there will be no arcing therebetween.

The improvement which comprises the instant invention includes an ice break attachment operable upon the opening or closing the main switch 16 to force rod-like members 45 apart thereby shattering any ice which may be formed therebetween.

In the embodiment of the invention shown in FIGS. 2-5, the ice breaking attachment comprises an arm 54 suitably secured to the cross bars 38 and 39 and extending upward therefrom. As seen in FIG. 3, arm 50 has an enlarged bulb-shaped head 52;, a reduced neck portion 53 and a body portion 54 which is attached to cross bars 38 and 39.

It can be seen from FIG. 4 that each rod 45 is bent inwardly near its free end to form a contact tip 46 and outwardly at its extreme end 47 to form a guide for the movable bypass rod 44. A pair of leaf springs 48 engage the outer end of each of the rods 45 for urging them toward each other.

When the switch and the load interrupter 12 are in their closed positions shown by the broken lines in FIG. 2, bypass rod 44 wil be disposed between the stationary bypass contacts 46. As shown in FIGS. 4 and 5, a stop bar 55 is mounted on the springs 48 by means of pins 56 and slots 57 for limiting the movement of bypass rod 44.

After trip arms have been moved sufiiciently toward their position shown by full lines in FIG. 2, so that load interrupter I2 is tripped open, the bulbous head portion 52 of ice break arm 50' will engage members intermediate their point of attachment and their contact tips 46. As head portion 53 :passes between rods 45, contact tips 46 will be spread outwardly. This will shatter any ice that may have formed on them which would tend to prevent bypass rod 44 from disengaging and at the same time relieve the contact pressure on bypass rod 44-.

Ice breaking arm is so proportioned that as the widest portion of its head 52 passes between rods 45, switch blade 16 will engage bypass rod 44 to move it away from contact tips 46 and toward its fully open position. Continued upward movement of trip arms 35 moves the narrow waist portion 53 of ice break arm 50 between rods 45 so that they can relax somewhat.

When the disconnect switch 10 is rec-losed, contact arm 16 will engage the lower cross bar 39 to move trip arms 35 downwardly toward their phantom position shown in FIG. 2. This moves the head portion 52 of ice break arm 50 downwardly between rods 45. Again stationary bypass contacts 46 are spread apart, thereby shattering any ice that may have formed while switch 10 was open. Also, while contacts 46 are in their extended or spread position bypass rod 44 will again slide therebetween so that when the upper end of ice break arm '50 reaches a position below rods 45 said bypass rod is embraced therebetween. As a result, ice does not interfere with the re-establishment of electrical contact between bypass rod 44 and stationary bypass contacts 42. In addition, the contact pressure exerted by rods 45 further enhances current interchange.

In an alternate embodiment of the invention illustrated in FIG. 6, the stationary bypass contacts 42a comprise a pair of parallel extending rod members 60 which are bent inwardly and then outwardly at their free ends to form the stationary contact structure 62. Here the ice break arm comprises a hook shaped member having a rearwardly extending upper portion 63 and a body portion 64 which is afilxed to cross bars 38 and 39. Each time trip arms 35 move between their open and closed positions shown by full and phantom lines, respectively in FIG. 2, portion 63 slides between the stationary contact structure 62 so that any ice that is formed thereon will be broken away.

In another embodiment of the invention shown in FIG. 7, the stationary bypass contacts 42b comprise a pair of parallel trod-like members 70 which are bent inwardly at 71 and outwardly at 72 to form contact tips for cooperatively engaging the bypass rod 44. In order to break any ice which may form between the contact tips, switch arm 16 is provided with an extension 74 which passes through said contact tips each time the switch is moved between open and closed position.

In a further embodiment of the invention illustrated in FIGS. 8 and 9 the bypass contact rods are looped at 81 for pivotally supporting an ice break member 82. Member 82 has an ice break arm 83 at its upper end and a pair of diverging operating arms 84 and 85 near its lower end. In addition, trip arms 35 are provided with a third cross bar 56 which engages the upper operating arm 34 when trip arms 35 are moved from their phantom to their full position so that ice break attachment 82 is also rotated from its phantom to its full position. As a result, ice break arm 83 is forced between contact tips 37 to remove any ice formed thereon. In addition, when trip lever 35 is returned to its closed position cross arm 86 engages the lower operating arm 85 to again move ice break arm 83 between contact tips 87.

While only a few embodiments of the invention have been shown and described, other modifications will become apparent once the inventive concept is known. Accordingly, it is intended to cover in the appended claims all such modifications falling within the true spirit of the invention.

I claim:

1. In the combination of a disconnect switch and a load interrupter, said disconnect switch having primary contact means including a movable switch blade, said load interrupter being in a by-pass circuit connected in parallel with said disconnect switch, said by-pass circuit including fixed and movable by-pass contacts operable by said switch blade to open after the opening of said primary switch means, and an ice break member pivotally mounted on said interrupter adjacent said fixed by-pass contacts and actuable by said switch blade upon movement thereof toward open position to engage said fixed by-pass contacts prior to the opening or reclosing of said by-pass contacts so that any ice formed thereon will bebroken away.

2. In the combination of a disconnect switch and a load interrupter, said disconnect switch having primary contact means including a movable switch blade, said load interrupter being in a by-pass circuit connected in parallel with said disconnect switch, said by-pass circuit including fixed and movable by-pass contacts operable by said switch blade to open after the opening of said primary switch means, said fixed by-pass contacts including a pair of opposed contact fingers, and an ice break member mounted on said switch blade and movable therewith in a plane that passes between said fixed by-pass contact fingers prior to the opening or reclosing of said by-pass contacts so that ice formed thereon will be broken away.

3. In the combination of a disconnect switch and a load interrupter, said disconnect switch having stationary contact means and a movable switch blade, said load interrupter being in a by-pass circuit connected in parallel with said disconnect switch and being operable to interrupt and close said by-pass circuit after the opening and reclosing of said disconnect switch, said by-pass circuit also including by-pass contact means having opposed contact fingers mounted on said circuit interrupter and a cooperating contact rod movable into and out of engagement with said contact fingers by the rotation of said switch blade while said load interrupter is open, said contact fingers being resiliently urged into contact pressure engagement with said contact rod, and contact pressure relief means operable by said switch blade for engagement between said contact fingers prior to the engagement or disengagement thereof by said contact rod whereby the opening and closing of said by-pass contacts is facilitated.

4. In the combination of a disconnect switch and a load interrupter, said disconnect switch including stationary contact means and a cooperating switch blade adapted to pivot into and out of engagement therewith, said load interrupter being in a by-pass circuit connect in parallel with said disconnect switch and having an operating arm engageable by said switch blade as it pivots away from and toward said stationary contact means for opening and closing said load interrupter respectively, by-pass contact means in said by-pass circuit including stationary bypass contacts having opposed contact fingers mounted on said circuit interrupter and a movable contact rod engageable by said switch blade after said load interrupter has been opened, and an ice break arm associated with said operating arm and disposed adjacent said con tact lingers and movable by said operating arm in a plane that passes therebetween, whereby said ice break arm is rotatable between said contact fingers prior to the opening and reclosing of said by-pass contact means so that any ice formed thereon will be broken away.

5. In the combination of a disconnect switch and a load interrupter, said disconnect switch including stationary contact means and a cooperating switch blade adapted to pivot into and out of engagement therewith, said load interrupter being in a bypass circuit connected in parallel with said disconnect switch and having an operating arm engageable by said switch blade as it pivots away from and toward said stationary contact means for opening and closing said load interrupter respectively, by-pass contact means in said by-pass circuit including stationary by-pass contacts having opposed contact fingers mounted on said circuit interrupter and a movable contact rod operable by said switch blade after said load interrupter has been opened, and an ice break arm pivotally mounted on said load interrupter adjacent said operating arm and movable thereby in a plane that passes between said contact fingers, whereby said ice break arm is rotated between said contact fingers prior to the opening and reclosing of said by-pass contact means so that any ice formed on said contact means will be broken away.

6. In the combination of an air break disconnect switch and a load interrupter, said disconnect switch including a stationary contact jaw and a cooperating switch blade adapted to pivot into and out of engagement therewith, said load interrupter being in a by-pass circuit connected in parallel with said disconnect switch and having an operating arm pivotally mounted thereon which is engageable by said switch blade as it pivots away from and toward said contact jaw for opening and closing said load interrupter respectively, by-pass contact means in said by-pass circuit including stationary by-pass contacts having opposed contact fingers mounted on said circuit interrupter and a movable contact rod operable by said switch blade after said circuit interrupter has been opened, and an ice break arm mounted on said operating arm and pivotable therewith in a plane that passes between said contact fingers, whereby said ice break arm is rotated between said contact fingers prior to the opening and reclosing of said by-pass contact means so that any ice thereon will be broken away.

7. In the combination of a disconnect switch and a load interrupter, said disconnect switch including stationary contact means and a cooperating switch blade adapted to pivot into and out of engagement therewith, said load interrupter being in a by-pass circuit connected in parallel with said disconnect switch and having an operating arm engageable by said switch blade as it pivots away from and toward said stationary contact means for opening and closing said load interrupter respectively, said by-pass circuit also including stationary by-pass contacts mounted on said circuit interrupter and a movable contact rod operable by said switch blade after said load interrupter has been opened, said load interrupter including an ice break member movable by said switch blade into engagement with said by-pass contacts prior to the opening and reclosing of said by-pass contact means so that any ice formed thereon will be broken away.

8. In the combination of an air break disconnect switch and a load interrupter, said disconnect switch including a stationary contact jaw and a cooperating switch blade adapted to pivot into and out of engagement therewith, said load interrupter being in a bypass circuit parallel with said disconnect switch and having an operating arm pivotally mounted thereon which is engageable by said switch blade as it pivots away from and towards said contact jaw for opening and closing said load interrupter respectively, said by-pass circuit having by-pass contact means including stationary by-pass contacts mounted on said circuit interrupter and a movable contact rod operable into and out of engagement with said stationary bypass contacts by said switch blade after said circuit interrupter has been opened, and an ice break member mounted on said operating arm and pivotable therewith into engagement with said stationary by-pass contacts prior to the opening and reclosing of said by-pass contact means so that any ice thereon will be broken away.

References Cited in the file of this patent UNITED STATES PATENTS 2,172,225 Schofield et al Sept. 5, 1939 2,426,009 Frank et a1. Aug. 19, 1947 2,905,794 Upton Sept. 22, 1959 

